According to an e-mail sent out by American University to its students:

“Today, December 17, AU Public Safety contacted the Metro Police Department about a suspicious item that appeared to be a grenade found in a residence hall room in Anderson Hall.

MPD reported to campus and advised that Anderson, Letts and Centennial Halls and offices be evacuated while they investigated the situation and removed the item. While this took place, at approximately 12:50 p.m, entry to campus was prohibited via the Rockwood and Massachusetts Avenue main gates.

The item was safely removed, deemed to be harmless, and campus operations returned to normal at approximately 1:20 p.m.”

No word on whether the item was actually a grenade or simple this album cover.